Soft tissue injuries and malformations secondary to trauma, congenital defects, infections, and oncologic resections are a source of significant morbidity in patients. At present autologous free flap reconstruction or local advancement flaps are the workhorses of reconstructive modalities for significant soft tissue and bony defects. While pedicled flaps and free flap reconstructions offer powerful tools for reconstruction, they are not without potentially serious side effects and donor site morbidity.
Autologous fat transplantation has been used in soft tissue reconstruction but is unpredictable. The advantage of using lipo-aspirated fat is two-fold: 1) minimal donor site morbidity providing a safe and readily accessible source for autologous cells, and 2) these procedures can be performed relatively easily without the concern for ischemic complications and early graft failures associated with vascularized free flaps. However, to date free fat grafts have been plagued with unpredictable high levels of reabsorption and resultant irregularities. Free fat graft failures and volume reduction appear to be related to mechanical stresses resulting in membrane damage from harvesting, early ischemic changes, and nutrient deprivation and insufficient vascular supply to the graft. These stressors lead to apoptosis and cell death. Subsequent, graft reabsorption results from removal of dead cellular debris following revascularization. This leads to inconsistent and undesirable results for soft tissue restoration. Since fat transplantation was first described by Neuber in 1893, little has been achieved to improve the results of free fat grafts. Thus far, efforts to attentuate the initial ischemic insult cells until sufficient vascularity can be established have been met with modest results. Thus, improving the vascular supply of the fat transplant alone may not be sufficient to greatly improve the results of fat transplantation. Preventing damage to cells during the procurement, handling, and/or transplantation of the fat graft is also important.
There remains a need for more successful transplantation of adipose tissue or cells derived from adipose tissue (e.g., adipocytes, stem cells) in cosmetic and reconstructive surgery. The ability to transfer a large volume of autologous adipose tissue for soft tissue reconstruction would provide a novel reconstructive option for potentially millions of patients, without the associated donor site morbidities. Additionally, it would provide a powerful tool for patients who have poor donor site options, and patients with the inability to tolerate the extended operating times required in flap reconstructions.